Tension control means



Dec. 2, 1969 J. NORTON TENSION CONTROL MEANS Filed March 19, 1968' 4 Sheets-Sheet 1 BY I W52 ATTORNEYS 4 Sheets-Sheet 2 Filed March 19, 1968 INVENTOR JOHN TON 5% ATTORN EYS Dec. 2, 1969 J. NORTON 3,481,011

TENSION CONTROL MEANS Filed March 19, 1968 4 Sheets-Sheet 3 I FIG. 6 4A INVENTOR JOHN NOR N B Mam ATTORNEYS 1366- 1969 J. NORTON TENSION GONT RQL MEANS 4 Sheets-Sheet 4 Filed March 19, 1968 INVENTOR JOHN 0 ON BY I W/QM ATTORNEYS United States Patent 3,481,011 TENSION CONTROL MEANS John Norton, Darwen, England, assignor to Leesona Limited, Great Britain, Northern Ireland, and the Isle of Man Filed Mar. 19, 1968, Ser. No. 714,225 Claims priority, application Great Britain, Mar. 23, 1967, 13,712/ 67 Int. Cl. D02h 13/22 US. C]. 28-35 9 Claims ABSTRACT OF THE DISCLOSURE Apparatus for winding a take-up beam from a plurality of supply beams. When the supply beams have different quantities of yarn thereon, the tension of the various strands would vary. Brakes are provided in the form of electromagnetic slip clutches for each of the supply beams in order to individually adjust the resistance to rotation of these beams. Such adjustment is initiated for each strand through movement of a pulley wheel responsive to the tension of the strand passing thereover. Such movement is reflected in a strain gauge connected in electric circuit through a voltmeter and a potentiometer to the brake of the beam from which the particular strand is being withdrawn. Thus, as the tension in any particular strand decreases, the drag applied to its beam by the slip clutch increases thus maintaining the strand tension to the desired level. Additionally, the strands are collected and passed over a roller which in turn actuates a strain gauge connected in an electrical circuit with all of the brakes to maintain the collective tension of the plurality of strands being wound onto the take-up beam at a desired level.

This invention concerns a yarn tension control means.

The object of the present invention is to maintain constant tension in yarn being supplied for example, to a sizing machine from a number of Warpers beams mounted on a creel.

According to the present invention there is provided a yarn tension control means including a first tension indicator, such as a strain gauge, adapted to enable a predetermined tension value to be set and a second tension indicator, such as a strain gauge, adapted to measure tension variation, said second indicator serving to actuate means adapted to control the tension in said yarn.

The invention will now be described further, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 and FIG. 1a together are a diagrammatic side elevation view of an apparatus embodying the invention,

FIG. 2 is an enlarged side elevation view of part of the apparatus of FIGS. 1 and 1a,

FIG. 3 is an end elevation view of part of the apparatus of FIG. 1 and FIG. 1a,

FIG. 4 is an enlarged, fragmentary, detail view of part of the apparatus of FIG. 1 and FIG. 1a, and

FIGS. 5 and 6 are further enlarged detail views of parts of the apparatus of FIG. 1 and FIG. 1a.

At the feed end of a beaming headstock, yarn is fed to a series of draw rollers 10 from a creel C containing for example twelve beams 11. Also mounted on the creel C are a plurality of guide rollers 12 around which yarn Y is adapted to be passed from the beams 11. Associated with each guide roller 12 is a strain gauge 13 (see in parice ticular FIG. 2) which is adapted to measure the tension in the yarn passed over the guide roller; the purpose of the strain gauge 13 will hereinafter be referred to.

The draw rollers 10 are located adjacent one end of the creel C and located between the draw rollers 10 and the creel C is a frame 14, on which three rollers 15, 16 and 17 are mounted. Yarn Y passes from the creel C under the first roller 15, over the second 16 and under the third 17 before reaching the draw rollers 10. This frame 14 will be referred to as the tension control frame.

Associated with the second roller 16 of the tension control frame 1 4 is a second strain gauge 18 which is adapted to measure the total tension in the yarn Y being fed off the creel C. The purpose of this strain gauge 18 will hereinafter be referred to.

Each of the beams 11 is mounted on the creel C in the following manner. The usual warp beam consists basically of a barrel, at each end of which is a circular flange 19 (FIGS. 3 and 4) on the outer face of which is a circular rufile or driving flange 19a. An adaptor 20 (see in particular FIG. 4) is provided at each end of the beam 11. Each adaptor 20 consists of a central shaft 21 of square cross section, at one end of which is rigidly mounted a flange 22. Adjacent the periphery of the flanges 22 is provided a peg 23. The peg 23 extends from the face of the flange 22 opposite to the shaft 21. A circular spacer 24 is mounted on the face of the flange 22 remote from the central shaft 21 and extends parallel to the peg 23. An adaptor 20' is fitted to each end of the beam 11 by locating the ruffle or driving flange 19a against the spacer 24 and locating the peg 23 in a recess 26 formed in the ruflle or driving flange 19a of the beam 11. Each end of the beam 11 with an adaptor 20 thereon, is located within a chuck 27 (see in particular FIGS. 4 and 5). Each chuck 27 is rotatably mounted on a shaft 27a journalled in bearings 27b (see particularly FIG. 4) mounted on the creel C. The chuck 27 consists of two sections 28 and 29 hinged together by pin 30 which when held in the closed position are adapted to support the square-sectioned shaft 21 of the adaptor 20. Thus the adaptor 20 and the beam 11 are mounted for rotation on the creel C. A safety guard 31 in the form of a forked plate is provided adjacent the chuck 27 and is fastened to the frame of the creel by a carrier block 31a. The arrangement is such that if the beam is inadvertently rotated whilst the chuck 27 is in the open position or the pivotal portion 27 is not locked by a screw 270 the beam 11 will fall from the chuck 27 but will only be displaced by a small distance represented by the amount by which the base 31b of a slot in the forked guard lies below the beam adaptor shaft 21.

The shaft 27a of the chuck 27 extends through the bearings 27b has attached to its end remote from the beam the armature (see particularly FIG. 4) of an electromagnetically actuated slipping clutch 32. The magnet half 101 of the clutch 32 is fixed to the creel C. The slipping clutch is adapted, in use, to apply a variable controlled braking torque to the beam shaft.

The guide roller 12 which is associated with each beam 11 is located at one end within bearings 33 (see particularly FIG. 6) mounted on the creel C. The other end of the roller is located within a bearing 34 which is mounted on an arm 35 (see particularly FIGS. 2 and 6) which is itself pivotally mounted on the creel C. The guide roller 12 is thus rotatably mounted and allowed slight pivotal movement towards the draw rollers 10 when yarn Y is passed around the roller 12. Attached to the arm 34 and to the creel C is the strain gauge 13. The strain gauge 13 (see particularly FIG. 2) is adapted, in use, to measure the tension in the yarn Y passing around the guide roller 12 when the yarn Y tends to cause the latter to pivot.

Electrically connected to the strain gauge 13 and adapted to measure the strain therein, is a voltmeter 36 (see particularly FIGS. 1, la and 3) calibrated to indicate tension in the the yarn Y passing over the guide roller 12. The voltmeter 36 is mounted on the creel C. A potentiometer 37 is incorporated in a housing carrying the voltmeter 36. The potentiometer 37 is electrically connected to the electromagnetic slipping clutch 32 and is adapted, in use, to preset a voltage supplied thereto.

The second strain gauge 18 (FIG. 1) is attached at one end to the tension control frame 14 and at the other end to the second roller 16 over which all the yarn Y entering the draw rollers is adapted to travel. This strain gauge 18 is electrically connected to a second potentiometer (not shown) which is adapted in use to control the supply to each of the electromagnetic slipping clutches 32.

In use, the machine is set up for operation with yarn Y from each beam 11 enwrapping its respective guide roller 12. Yarn Y from all of the beams 11 is then passed over the first, second and third rollers 15, 16 and 17 of the tension control frame 14 and into the draw rollers 10.

The sizing machine is started and yarn Y is drawn off beams 11 on the creel C, through the draw rollers 10 and onto a take-up beam 38.

Current is supplied, via the second potentiometer to each of the electromagnetic slipping clutches 32. The initial tension in the yarn Y from each beam 11 is measured by the strain gauge 13 associated with the appropriate guide roller 12 and is indicated on the appropriate voltmeter 36. The potentiometer 37 associated with the voltmeter is adjusted, thereby adjusting the input voltage to the clutch 32 to produce the required tension in the yarn Y leaving the beam 11, which is then indicated on the voltmeter 36. This operation is carried out on all the beams 11 and thus the initial tension in all of the yarn Y passing into the draw rollers 10 is constant.

During operation of the machine, as beam diameter decreases, the tension in the yarn Y increases slightly. The increase in tension is sensed by the second strain gauge 18, the output from which alters the setting of the second potentiometer thus to supply a reduced input voltage to the electromagnetic slipping clutches 32. This reduced voltage will reduce the braking torque in each clutch 32, thus restoring the required tension in the yarn Y.

As the beams 11 are unwound, their diameters are gradually reduced from a full to an empty condition. The second potentiometer is so arranged that its limits of adjustment are substantially proportional to the diametrical limits of a fully wound and a fully unwound beam 11.

In the event of a number of beams 11 being unwound which have varying starting diameters the respective beam diameters will diminish during operation at varying rates producing various values of tension. In this case, therefore, it may be found advantageous once or twice throughout the unwinding operation, to readjust the first potentiometers 37 to ensure that the tension in the yarn Y from each of the beams 11 is constant.

The invention is not restricted to the above details. For example, the tension control frame 14 may be dispensed with, in which case the potentiometers 37 associated with each beam must be readjusted frequently throughout the unwinding operation in order to maintain a constant tension in the yarn Y fed to the draw rollers 10.

The beam creel C could also be used in conjunction with a sizing machine finally to assemble sized yarn onto a weavers beam.

In addition the electrical strain gauges, potentiometers, voltmeters and clutches may be replaced by equivalent hydraulic or pneumatic means. Also the arrangement by which a beam 11 is fitted to the creel C may be adapted in any convenient manner to suit individual requirements.

In order that the square sectioned shafts 21 can be disposed in the same attitude, the recess 26 (FIG. 4) extends over an arc of 45 to allow for adjustment of the positions of the shafts 21.

What is claimed is:

1. A system for controlling the tension of strands withdrawn from separate sources of supply and commonly collected, comprising means for controlling the tension of said strands individually responsive to the tension of the strand being controlled and collectively responsive to the collective tension of the strands.

2. A system as set forth in claim 1 in which the controlling means comprises brakes, one for each of said strands, said brakes being operable for providing a variable drag on the associated strand, means for sensing the tension of the strands, and means connecting the tension sensing means with said brakes for operating said brakes to vary the drag on the strands responsive to strand tension.

3. A system as set forth in claim 2 in Which said tension sensing means includes first tension sensors, one for each of said strands, for sensing the tension of the associated strand, and a second tension sensor for sensing the tension of the collective strands.

4, A system as set forth in claim 1 wherein said sources of supply are rotatably mounted beams from which the strands are withdrawn, the controlling means comprises: adjustable brakes, one for each of said beams, for retarding rotation of the associated beam to control the tension of the associated strand; first means, one for each of the strands, for sensing the tension of the associated strand; means connecting each said first means with the brake of the associated strand for varying the drag on the associated beam and thereby the tension of the strand;

second means for sensing the collective tension of the strands; and means connecting said second means With said brakes for concurrently varying the drag on the beams and thereby the tension of the strands.

5. A system as set forth in claim 4 in which said brakes are electromagnetic slip clutches; said first means each include: a guide roller for receiving the associated strand, means mounting said guide roller for movement to and fro responsive to variation in strand tension, a strain gauge, means operatively associating said guide roller and said strain gauge to operate said strain gauge responsive to variation in strand tension, a potentiometer and a voltmeter, and the first connecting mean-s connecting said potentiometer and said voltmeter in circuit with said strain gauge and the associated clutch for operating the clutch and controlling the tension of the associated strand; and said second means includes: a guide roller for receiving the collective strands, means mounting the last said guide roller for movement to and fro responsive to variation in the collective strand tension, a second strain gauge, a potentiometer and a voltmeter, and the second connecting means connecting the last said potentiometer and voltmeter in circuit with the said second strain gauge and said clutches for operating the clutches and controlling the tension of the strands.

6. A system for maintaining substantially uniform tension in strands withdrawn from separate beams on a creel, comprising first means, one for each of the strands, said first means being operable for applying a varying drag to the respective strand, and second means, one for each of the strands, for operating said first means of the associated strand to maintain substantially uniform drag on the associated strand.

7. A system as set forth in claim 6 in which said first means each includes an adjustable slip clutch operable for applying a variable resistance to rotation to the respective beam; and said second means include tension sensors, one for each of said strands, for sensing the tension of the respective strand, and means connecting said tension sensor with the associated slip clutch for adjusting the tension of the associated strand.

8. A system as set forth in claim 7 in which the connect 5 6 ing means are adjusted so that substantially the same References Cited tension is provided each strand.

9. A system as set forth in claim 8 including third means UNITED STTES PATENTS connected With said slip clutches for concurrently vary- 2,924,869 2/1960 Kleln et 3L 2835 X ing the resistance to rotation of said beams and the tension of all said Strands 5 LOUIS K. RIMRODT, Prlrnary Examiner 

